Viscoelastic Finite Element Technique for Computing Rutting of Asphalt Concrete Pavement Including Aging Factor

Abstract

Rutting is often responsible for premature maintenance and rehabilitation activities reducing service life of the pavement. Several finite element computer programs for analyzing flexible pavements have been developed over the years. Most of these programs (like ANSYS)did not take into consideration the effect of the aging factor on the behavior of viscoelastic asphalt concrete layer. The present work uses a displacement based finite element method to compute vertical compression strain and rutting depth for a flexible pavement system of three layers taking into consideration the aging (temperature) effect depending on Williams, Landel and Ferry (WLF) equation. Two popular tire/axle configurations with different tire pressure are investigated using the traditional approximate circular tire print. The results showed that the difference between the proposed technique and some other methods neglecting aging effect ranges from 5% to 15% while the difference between the proposed technique and linear elastic Pro-Engineer (version 4) program ranges from 10% to 17%.